Extremely high metal-on-metal pressures are present in newer automatic and manual transmissions such as step automatic transmissions, continuously variable transmissions, and manual or automated manual transmissions. High pressures are also present in various gear drive components such as automotive differentials and power transmission gear drive components.
In this regard, it is widely known that lubrication has a profound effect in reducing wear associated with automotive machinery, such as engines, transmissions, and other equipment having moving parts. Lubrication separates the moving surfaces with a film which can be sheared with low resistance, without causing damage to the surfaces.
Carboxylic acids, such as caprylic acid, are useful as corrosion inhibitors and lubricity improvers in lubricants and fuels. Unfortunately, caprylic acid causes corrosion in machine, engine, and transmission parts that contain lead as part of the material of construction.
U.S. Pat. No. 6,750,183, is directed to crankcase lubricating oils comprising a major amount by weight of an oil of lubricating viscosity; a minor amount by weight of a high molecular weight, nitrogen-containing dispersant; and an amount of an oil soluble, or oil dispersible aromatic hydrocarbyl oligomer sufficient to provide the lubricating composition with improved soot dispersing properties, wherein the dispersant may be made from monounsaturated carboxylic acids.
U.S. Pat. No. 6,748,905, is directed to a process for reducing engine wear in the operation of an internal combustion engine, comprising: (A) recirculating at least part of the exhaust gas from the engine to the intake air supply of the engine; and (B) operating the engine using a water-blended fuel composition made by combining: (i) a normally liquid hydrocarbon fuel; (ii) water; and (iii) at least one surfactant. The surfactant may be one or more acylating agents, such as a carboxylic acid reacted with, for example, an amine.
U.S. Pat. No. 6,746,778, is directed to a metal substrate with a corrosion-proofing bond coating containing adhesion-conferring polymers, based on organic compounds, such as cinnamic acid.
U.S. Pat. No. 6,001,141, is directed to low sulfur content fuel compositions containing additive compounds which exhibit improved lubricity. The additive compounds include a carboxylic acid substituted by at least one hydroxyl group, and derivatives of the carboxylic acid substituted by at least one hydroxyl group.